The present invention is directed to testing apparatus for image intensifiers and in particular to an apparatus for measuring the light intensity gain performance of an image intensifier.
Low light level viewing systems of the type which include image intensifiers are becoming more and more popular. Under continued use, many intensifiers of low light level viewing systems suffer a gradual loss of luminous gain. Unfortunately, the user may not be able to tell when performance is marginal. As a result, the usual procedure is to use a system until excessive gain decay is suffered and then to return it to the manufacturer for repair. This situation occurs because most users of such low light level viewing systems are not equipped to make the required intensity gain performance measurements.
Manufacturers of low light level viewing systems are well equipped to make such gain performance measurements. However, the only equipment presently available to such manufacturers for making these measurements are general-purpose photometers and special low intensity light sources all of which are not portable and thus not suitable for use where low light level systems are generally employed. Additionally, all of these instruments have far more flexibility than is actually required for gain performance measurements and are therefore far more expensive than necessary.
It is therefore an object of the present invention to provide a portable apparatus for measuring the gain performance of an image intensifier in a low light level viewing system.
It is another object of the present invention to provide an apparatus for measuring the gain performance of image intensifiers which is both accurate and inexpensive.